The scientific, spooky reason why vampires might have been oh-so real

While vampires are only really thought of as legends—and classic story characters (hello, Dracula!)—there’s now scientific evidence that the spooky bloodsuckers might have actually been (or at least based on) real people.

Sensitivity to light, paleness, taking in lots and lots of blood—sound familiar? Although the real-life vampires didn’t quite run around biting people’s necks, the origin of all the stories are starting to make some sense, thanks to a new study.

Because exposure to sunlight could cause painful blisters, those affected could only come out at night.

There’s a group of blood disorders called porphyrias, and one of them—erythropoietic protoporphyria (EPP)—commonly occurs in childhood. Because exposure to sunlight could can painful blisters in young ones who suffer from the condition, the kids could really only come out at night.

“People with EPP are chronically anemic, which makes them feel very tired and look very pale with increased photosensitivity because they can’t come out in the daylight,” said Barry Paw, MD, PhD, in a press release. “Even on a cloudy day, there’s enough ultraviolet light to cause blistering and disfigurement of the exposed body parts, ears and nose.”

While the modern treatment is blood transfusions to help fight off the disorder’s symptoms, that wasn’t the case in ancient times: When the individuals who suffered from EPP came out at night, they might’ve consumed animal blood for symptom relief, Science Daily reported. (This whole vampire thing is really starting to make sense, right?)

With Halloween right around the corner, you’re bound to see plenty of vampire fangs and capes making the rounds, and now you know the condition that may be responsible for the folklore. But vampire jokes aside, keep in mind that EPP is also a real, super-rare disorder that affects 1 in every 74,300 people.

“Although vampires aren’t real, there is a real need for innovative therapies to improve the lives of people with porphyrias,” said Dr. Paw. Hopefully bringing it to light will assist in finding a cure.